That's why they chose to find a way around it by insisting that "preloaded" apps are exempt, due to the relatively (incredibly) weak rules set in place by the FCC.
The death star does quite a few things to try and usher people away from their grandfathered unlimited plans... tethering after they hit the 2gb limit, and now this? Ridiculous.
so, all apple needs to do is make facetime downloadable and stop preloading it?
I propose Apple add a "FaceTime 3G unlock" app to the store that simply disables AT&T's FaceTime block. According to AT&T's logic they wouldn't be able to block that.